Annoyed with AF and I have a question

K • Married, 3yo girl, second girl in the way

I’m 6 days late at this point. I tested at DPO because I was so sure but knew it was early. Waited for af. Tested the morning of 3 days late and then again this morning at 6 days late. (BFNs)

The week after 10 DPO test I stopped having so many symptoms that I chalked up to pregnancy (probably because it was all in my damn head) so at this point I don’t believe I’m pregnant

But AF is being a bitch and hiding out so that I can’t start my cycle over and count my days. My temp is around 97.1 F these days.

How long would you ladies wait before assuming you just arent getting a period this month (didn’t get one in November) and then how do you know what cycle day you’re on? Would I still ovulate??

I used to be SOO perfectly regular when on the pill... (stopped in August)